Patients who have difficulty swallowing (dysphagia) resulting from nerve or structural damage to the upper digestive tract have difficulty safely consuming liquids. Accordingly, such patients typically use commercially available thickening agents to safely consume nutritionally adequate amounts of foods and liquids. See generally C. Pelletier, Dysphagia 12, 74-78 (1997).
Pregelatinized starch, also known as cold-water-soluble starch, is available as a thickening agent (see, e.g., BeMiller and Whistler, Ch. 4 in Food Chemistry, pg 204, (O. Fennema Ed. 3d ed. 1996). Such materials are conveniently provided in dry powder form and can be readily reconstituted in a variety of foods and beverages to increase the viscosity thereof. However, such materials do not serve as a source of protein, and obviously serve as an additional source of carbohydrate. For dysphagia patients, where food consumption is difficult, it is desirable to find ways to allow the patients to increase protein consumption, and/or decrease carbohydrate consumption. Accordingly, there is a need for a dry protein product that can be used as a viscosity modifying agent.
Dry protein products that can be used as a thickening agent are not simple to produce. To be useful as a thickening agent the product must be conveniently mixed in a variety of foods, at a variety of pH, temperature, and other conditions. Such a product would be a "cold-set" protein gel, but the production of cold set protein gels has been difficult. C. Bryant and D. Elements (Trends in Food Science and Technology 9, 143 (1998)), describe progress towards cold-setting whey protein ingredients, but do not describe a dry powder that can be used to produce a cold-set protein gel.
In the neutraceutical and food industries, there has been considerable interest in the development of fat substitutes. Protein-based fat substitutes such as SIMPLESSE.RTM. are attractive from a nutritional perspective, and protein-based fat substitutes derived from a dairy product such as whey protein are particularly attractive. Thickening agents would possess many of the features desired in a fat substitute. However, some products that have been developed as fat substitutes to date lack thermal stability and are difficult to use in baked products, or have not been provided in dry powder form. A variety of such products are reviewed in G. Ziegler, U.S. Pat. No. 5,147,677 (See also N. Singer, U.S. Pat. No. 4,855,156). Accordingly, there is a need for a dry powder protein product that can be used in a variety of food applications.